The invention is an injection device for injecting fuel into an engine and includes an arrangement wherein there is a flow of fuel through the injection device at least when it is not injecting fuel into the engine. This flow provides uniflow scavenging and cooling of the injection device and prevents vapor lock.
Fuel injection devices are most commonly used for gasoline injection in internal combustion engines of motor vehicles. Fuel is provided through an inlet to a nozzle arrangement which is screwed into the cylinder or cylinder head of the engine. This part of the engine is subject to high temperatures when the engine is operating, and the materials used for the nozzle arrangement are normally heat conductors so that there is a danger of at least partial evaporation of the fuel in the nozzle arrangement awaiting injection. Such evaporation is undesirable since it increases the pressure in the nozzle arrangement, and may impede or prevent the subsequent supplying of fuel to the nozzle.
This problem may be prevented by providing additional means for cooling the nozzle system, or if the nozzle system is used together with an injection pump, for cooling of the combined unit. It would be desirable however, to provide an arrangement for preventing the formation of vapor lock in the nozzle arrangement or the combined nozzle and pump, which would utilize the existing structure of the nozzle arrangement and not require any additional components or alterations.